Strategies for improving fuel efficiency in the Portuguese trawl fishery

The recent rise in oil prices has brought renewed attention to energy savings in the fishing industry, and particularly in trawling. Coastal trawlers spend most of their time on fishing grounds near the coast. In such cases, the most successful energy-saving modifications ought to result from changes in the fishing gear and towing conditions. The purpose of this study was to identify the energy-economy potential for Portuguese fish trawlers after altering a vessel's operating conditions and improving its trawl gear performance. Two trawlers, named Tricana de Aveiro and João Macedo were selected as subjects in this project. Both vessels work with gear of similar design and size. Experimental sea trials were carried out to elucidate the actual vessel and gear performance. A model trawl was then built and tested in a flume tank, which provided the basis for improving the gear design. Full-scale trials were then carried out with both vessels using the modified trawls in order to assess changes in gear performance. The new trawls maintained their previous ability to catch species of different ecological groups and consumed less fuel at the same commercial trawling speed. An economic study showed potential increases in the net cash flow (NCF) of up to 27% over the range of operational navigation and trawling speeds. Having demonstrated the performance of the new trawls, the skippers of both vessels subsequently adopted the new design for commercial fishing.     

论编辑和作者的交流与合作

编辑与作者交流中存在的问题 ,是由作者提供的稿件质量不高 ,人情稿、关系稿充斥和一些编辑不负责任的态度和做法引起的。二者交流应持无私的态度 ,相互尊重 ,彼此体谅 ,加强沟通。双方交流的方式与方法概括起来有当面交流、书信交流等     

On the age and growth of bogue,Boops boops (L.), from the Portuguese coast

Abstract Between 1984 and 1990, a total of 4892 bogues, Boops boops (L.) were caught in Peniche and 4352 in Algarve, with the total length varying from 6 to 40 cm. Age determination was carried out using direct reading and back-calculation on the otoliths. Von Bertalanffy growth equations, based on mean lengths per age group, were established for both samples and using both methods. Applying the Hotelling T² test to the growth parameters of those equations, it was concluded that there were no significant differences between them. This conclusion allowed the validation of the two methods employed, and the combination of the data from Peniche and Algarve into one single age-length key from which a growth equation for the Portuguese coast was calculated and described as: L_t = 45.918 {1-exp [-0.124 (t + 2.628)]}.     

Components of variation,heritabilities and correlations for indices of sprouting tolerance and seed dormancy in Triticum spp.

Summary RFLPs were used to study the genetic relationships of 31 Portuguese coles (Brassica oleracea L.) representing the different ecotypes or landraces grown in Portugal. Other cole crops such as Jersey kale, Chinese kales, common cabbages, broccolis and cauliflower, two nine-chromosome wild species, and one accession of turnip also were included to determine the evolutionary relationships of Portuguese coles to other related coles. Principal coordinates and cluster analyses were conducted using a package of computer programs and RFLP data from 55 nuclear DNA probes, detecting 291 polymorphic restriction fragments. The results showed that the 48 accessions clustered into five groups: (a) a dispersed group with turnip and the wild brassicas; (b) Chinese kales; (c) broccolis and cauliflower; (d) a disperse group including Algarve and Jersey kales, thousand head kale, cabbages, and savoy cabbage; (e) a large and compact group containing all Portuguese tronchuda cabbages and kales. This unique and closely related group containing Portuguese tronchuda cabbages and kales could be further divided into five subgroups corresponding to the major areas of cultivation. The phenetic groupings of Portuguese tronchuda cabbages and kales based on RFLP data corresponded more with their geographic origins (collecting sites) than with their morphological similarities. A mechanism involving geographic isolation and frequent intercrossing within local areas is proposed to explain genetic relationships among Portuguese tronchuda cabbages and kales.     

Numerical taxonomy of Portuguese Tronchuda cabbage and Galega kale landraces using morphological characters

Summary A morphological study was carried out to determine the relationships among Portuguese cole landraces using 58 accessions belonging to: (i) Portuguese Tronchuda cabbage (Brassica oleracea var. tronchuda Bailey syn. var. costata De Candolle, Couve Tronchuda); (ii) Portuguese Galega kale (B. oleracea var. acephala De Candolle, Couve Galega); and (iii) other economically less important coles such as Algarve cabbages (B. oleracea var. capitata L., Couve do Algarve or B. oleracea var. sabauda L., Couve Repolho-lombarda do Algarve). The cole accessions were collected from the growers, studied under field conditions during two consecutive years, and characterized using 46 morphological characters from seedling stage to ripe silique. Morphological data were analysed by numerical taxonomy techniques using UPGMA (Unweighted Pair Group Method Using Arithmetic Averages) and by principal component analysis (PCA). Phenograms based on correlation and distance coefficients showed the existence of 8 main groups (A-H). Five of these groups correspond to Tronchuda cabbage landraces: (A) Couves de Trás-os-Montes; (B) Couves do Minho; (C) Couves from Central Portugal; (D) Couve Portuguesa; (E) Couves from Southern inland Portugal. The three other groups correspond to: (F) cabbages; (G) miscellaneous coles; and (H) Galega kales. Landrace groups are primarily associated with morphological differences among accessions and secondly with accession geographical origin. The interannual character variation did not affect the clustering patterns of the accessions and therefore the stability of landrace classification. PCA was congruent with the landrace groups defined by the phenograms and gave supplementary information on the usefulness of the characters for the definition of the various groups.     

法兰地草莓组织培养快繁技术研究

以法兰地草莓为试材,对草莓匍匐茎茎尖进行组织培养,筛选出适宜法兰地草莓外植体升汞（0．1％）处理的最佳时间为3min、诱导分化培养基为MS＋0．50mg／L 6-BA＋0．01mg／L NAA、继代增殖及生根培养基为MS＋0．50mg／L 6-BA＋0．01mg／L NAA,以松树林的腐质土与珍珠岩的比例为9：1的基质,移栽试管苗成活率达95％,并且生长健壮。